Year	% of total
1960	96.35036496350364
1961	89.43661971830986
1962	90.00000000000001
1963	90.63444108761328
1964	80.94059405940594
1965	86.40776699029125
1966	85.46637744034706
1967	82.94573643410853
1968	79.29292929292929
1969	68.48920863309353
1970	72.86135693215338
1971	61.07784431137725
1972	57.39219712525667
1973	63.096500530222684
1974	67.36183524504693
1975	70.73170731707317
1976	69.01521216973579
1977	73.9770867430442
1978	65.79139314369074
1979	71.28482972136221
1980	74.54831107619796
1981	74.44529456771232
1982	73.9460370994941
1983	73.84615384615384
1984	76.31578947368422
1985	75.82222222222222
1986	76.21359223300969
1987	72.97543221110101
1988	68.51063829787233
1989	61.23348017621145
1990	57.522834507042255
1991	56.943362218370886
1992	50.00454545454546
1993	47.31461636828645
1994	46.20257743362831
1995	60.42616586538462
1996	67.46918719211821
1997	69.97415458937198
1998	76.66202090592334
1999	75.87373115577888
2000	58.3053
2001	64.41650190114069
2002	59.928493317132435
2003	66.49708013172338
2004	64.698025477707
2005	66.60320754716982
2006	59.30945340501792
2007	59.603978405315615
2008	56.13157450076805
2009	53.564109589041095
2010	52.371781914893624
2011	50.73612158054711
2012	59.43728695652174
2013	54.37275862068965
2014	52.66881011403074
2015	49.60601175894169
2016	49.85490976399815